HK1249080B - Vacuum packaging machine and monitoring system for vacuum packaging machine - Google Patents

Description

Vacuum packaging machine and monitoring system for vacuum packaging machine

Technical Field

The present disclosure generally relates to the field of packaging, and more particularly to a vacuum packaging machine and a monitoring system for the vacuum packaging machine.

Background Art

Vacuum packaging provides an effective method for packaging many products, including food. Using vacuum packaging can increase the shelf life of packaged food by removing air from the packaging and reduce the volume of the packaged product.

Many individual machines from various sources can be used to assist in vacuum packaging of products. Each of these machines follows a basic pattern: the product is placed in a packaging material, typically a thermoformable plastic film, the air is removed from the packaging material, and the packaging material is sealed around the product.

In order to efficiently produce large commercial quantities of vacuum-packed products, vendors have developed large-scale production equipment to achieve vacuum packaging on a large scale. Such equipment typically follows several stages, including: placing the product inside the package, loading the product/package combination into a vacuum chamber, drawing a vacuum in the vacuum chamber to remove air from the package, using heated rods to melt the edges of the package together to seal the package, trimming the packaging material to minimize the volume of the packaged product, and placing the packaged product on a conveyor for accumulation into other containers.

Evacuating the package takes a lot of time because a vacuum pump is usually used to reduce the air pressure in the vacuum chamber. Therefore, large-scale production equipment can use a turntable of the vacuum chamber to improve the time utilization of evacuating the vacuum in each vacuum chamber.

The vacuum chamber itself may be formed from two components, commonly referred to as a platen, which forms a stand or platform for the product in the unsealed package, and a chamber lid, which forms an airtight cover that sits on top of the platen once the product is placed on it. The combined platen/chamber lid may also typically be provided with an airtight connection for connecting the combined chamber lid/platen (when combined together, referred to as the "vacuum chamber") to one or more vacuum pumps for evacuating air from the vacuum chamber (and thereby also from the package containing the product). The vacuum chamber may additionally be provided with means for sealing the package under vacuum, such as a heated metal element for melting the package to form a seal that prevents air from re-entering the package when the package is removed from the vacuum chamber.

To address the issue of prolonged vacuum chamber "dead time" during the vacuum cycle, multiple vacuum chambers are typically installed, often with different platen and chamber lid combinations. The ability of the vacuum chamber to maintain vacuum is crucial to the efficiency with which the machine can package the product. Products that do not experience sufficient vacuum before sealing may need to be rejected, resulting in waste. Detecting sealing issues is crucial. Sealing issues can result in a significant amount of substandard product being distributed to consumers or wasted due to rejection before the problem is discovered, and can also lead to significant downtime of the production equipment to diagnose and correct the defect.

Summary of the Invention

In order to improve the efficiency of using vacuum packaging equipment with multiple vacuum chambers, a monitoring and management system has been developed that uses the vacuum achieved for each individual cycle of the vacuum packaging equipment to identify problematic product/package units and vacuum chamber and vacuum chamber cover/pressing plate combinations, so that problems during production can be quickly identified and the system can be managed to achieve the most efficient implementation of the vacuum packaging equipment.

In one aspect, the present invention relates to a monitoring system for a vacuum packaging machine having a plurality of platens and chamber lids, and a vacuum pump for pumping air from a vacuum chamber formed by the platens and chamber lids. The monitoring system may include a vacuum sensor for measuring the pressure level achieved in the vacuum chamber formed by the platens and chamber lids. The monitoring system may also include a platen identifier for identifying the platen used to form the vacuum chamber to which the vacuum sensor is connected, and a chamber lid identifier for identifying the chamber lid used to form the vacuum chamber to which the vacuum sensor is connected. The monitoring system may also include a data logger for recording the vacuum achieved in the vacuum chamber for each platen and chamber lid combination that together form the vacuum chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a top view of a six-chamber lid, ten-platen vacuum packaging system including a sensor system according to one embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating vacuum performance of a seven-chamber lid, twelve-platen vacuum packaging system according to one embodiment of the present invention.

FIG3 is a schematic diagram illustrating vacuum performance of a seven-chamber lid, twelve-platen vacuum packaging system according to one embodiment of the present invention.

FIG. 4 is a schematic diagram that enables an operator to identify a combination whose data is desired to be viewed.

FIG5 is a schematic diagram of a method for enabling an operator to set monitoring parameters of a monitoring system according to an embodiment of the present invention.

6 is a schematic diagram of product position sensor outputs of a monitoring system according to one embodiment of the present invention.

7 is a schematic diagram of product sensor outputs of a monitoring system according to one embodiment of the present invention.

FIG8 is a schematic diagram of a vacuum sensor output of a dual-stage vacuum pump system according to an embodiment of the present invention.

DETAILED DESCRIPTION

In the following description, specific terms are used for convenience and are not limiting. Unless otherwise specified herein, the terms "a," "an," and "the" are not limited to one element but should be interpreted as meaning "at least one." The term includes the above-mentioned words, their abbreviations, and words with similar meanings.

As shown in FIG1 , the controller system can be connected to a vacuum packaging apparatus 100. The vacuum packaging apparatus 100 can include a plurality of platens 102a, 102b, 102c, ... and chamber lids 104a, 104b, 104c, ..., which can be combined to form a single vacuum chamber 106. The number of platens 102 and chamber lids 104 can be equal or unequal, such that different platens 102 can be combined with different chamber lids 104 to form the vacuum chamber 106 at different times.

For purposes of the following discussion, an apparatus is described having six chamber lids 104 and ten platens 102. However, the present invention can be readily implemented with different numbers of platens 102 and chamber lids 104, including apparatus 100 having an equal number of platens 102 and chamber lids 104. In the event that the number of platens 102 is not equal to the number of chamber lids 104, the resulting combination is the result of sequentially using each platen 102 and chamber lid 104, such that for the configuration of six chamber lids and ten platens in question, the first six chamber lids are matched with the first six platens, then the chamber lid to be reused, starting with the first chamber lid, is now matched with the seventh platen, the second chamber lid is now matched with the eighth platen, and so on, continuing sequentially through the chamber lids and platens.

The controller may preferably be provided with pressure sensors 108, 110 configured to determine the vacuum level achieved in any one of the vacuum chambers 106 during a vacuum cycle. Where multiple vacuum pumps are used to evacuate air from the vacuum chamber, a pressure sensor 108, 110 may be associated with each vacuum pump. For example, where two vacuum pumps are sequentially connected to the vacuum chamber 106 via a slip ring or other channel to enable evacuation of air from the vacuum chamber 106, a sensor 108 may be provided in a port or passage associated with the first pump to measure the vacuum drawn by the first pump in the chamber 106 containing the product and packaging, while a sensor 110 is connected to a secondary pump.

The system may be further provided with additional sensors 112, 114, for example, to identify the particular platen 102 and/or chamber lid 104 currently in use. In one embodiment, the system may use an optical sensor that detects features on the platen 102 that are identified as the platen numbered "1" and features on the first chamber lid 104 to identify the chamber lid as the chamber lid numbered "1," with a counter 116 used to identify successive platens 102 and chamber lids 104 until a platen 102 and/or chamber lid 104 having visual features identifying the chamber lid and/or platen as the first chamber and/or platen is again detected. Alternatively, in the case where the platen 102 and chamber lid 104 are combined in sequence, the controller can identify the current platen and chamber lid using a counter 116. That is, arbitrary values (e.g., platen number "1" and chamber lid number "1") have been assigned to the first platen and chamber lid, and based on the numbers of the current chamber lid 104 and platen 102, the current platen and chamber lid can be determined by incrementing the platen and chamber lid identifiers each time a platen or chamber lid is used, without resorting to visual sensors or other detection devices. Alternatively, each platen 102 and chamber lid 104 can be uniquely identified so that a record can be maintained throughout the startup and shutdown of the controller system. In the case where a counter system is used to track specific platens 102 and chamber lids 104, the counter can be indexed by the operator at the beginning of operation to ensure that the platen 102 and chamber lid 104 identifiers are maintained during different operating periods. In an alternative embodiment, the platen and chamber lid identification sensors may be visual sensors that detect visual markings (e.g., bar code labels) on each platen 102 and chamber lid 104, enabling a data logger to record the platen 102 and chamber lid 104 identifiers so that they can be correlated with vacuum readings without the need for a counter system.

In addition to the components for identifying the platen 102, the chamber lid 104, and the vacuum level achieved, the system can be provided with additional sensors for determining operating parameters. Sensor 118 can be used to determine when the platen 102 has product being packaged on it. This can be achieved in a variety of ways, for example, by using a visual sensor that determines when the field of view is disrupted by the presence of product (i.e., the sensor uses a light source and a receiver, and placing the product between the light source and the receiver will prevent the light from reaching the receiver), or by using a mass sensor to weigh the platen to determine whether the product is present (i.e., whether the mass of the weighed platen is greater than the weight of the platen after unloading).

Another sensor 120 can be used to determine the timing associated with measuring the vacuum level, such as when a port on the vacuum chamber 106 is placed in communication with a vacuum pump. To achieve a greater flow rate, the vacuum chamber 106 can be connected to a vacuum source only during the time the vacuum chamber is enclosed with products and packages. Thus, measuring the vacuum applied at times other than when the vacuum is applied to the enclosed vacuum chamber 106 may provide less valuable information.

Additionally, the sensor 122 may be configured to indicate each time a package is removed from the vacuum packaging system 100 so that a timing indication may be obtained, thereby enabling tracking of the package to a downstream location.

Since the process employed in a multi-vacuum chamber system involves some chambers being loaded, some being depressurized, and some being unloaded, costs can be saved by sequentially using one or more common vacuum pumps for all vacuum chambers rather than providing one or more vacuum pumps for each vacuum chamber. Similarly, by associating pressure measurement equipment with the vacuum pumps rather than the chambers, the amount of required sensing equipment can be reduced.

In one embodiment where a single vacuum pump is applied sequentially to different vacuum chambers 106, measuring the vacuum drawn in a particular vacuum chamber provides information regarding whether an adequate vacuum is being drawn on the packaged product, and in the case of a system using chambers and platens that are not serially associated with each other, information regarding the effectiveness of a particular chamber and a particular platen combination.

In such a system, a single vacuum pump may be connected to successive vacuum chambers in turn, by using pressure sensors 108, 110 placed on the side of the vacuum pump that is alternately connected to the vacuum chambers 106 to obtain a measurement of the vacuum when the vacuum pump is connected to the vacuum chambers, so that only a single sensor 108 needs to be deployed.

In an alternative embodiment, a two-stage vacuum pumping system may be preferably used, in which different vacuum pumps are sequentially connected at different times. In such a system, a first sensor 108 may be associated with a port on the first vacuum pump, wherein the port is communicatively connected to the vacuum pump 106 when connected, and a second sensor 110 may be associated with a port on the second vacuum pump, wherein the port is communicatively connected to the vacuum pump 106 when connected. Thus, the vacuum achieved at the vacuum pump 106 will depend on the vacuum achieved by the first pump when connected and the vacuum achieved by the second pump when connected. Simply measuring the vacuum level achieved after connecting the two vacuum pumps may provide ambiguous information regarding the source of any insufficient vacuum achieved in the vacuum chamber.

Thus, when using such a system, it is preferred to measure both the first pumped vacuum and the second pumped vacuum so that it can be determined whether the failure to achieve the desired vacuum is due to one or both of the pumps, or to the vacuum chamber 106 itself. The timing of the measurement is therefore relevant to the meaning of the measurement, and the optical sensor 120 can be used to determine the position of the vacuum chamber 106, for example, when it reaches a first position where the first vacuum pump can be connected to the vacuum chamber. Alternatively, one or more contact sensors can be used to obtain the same information.

The timing of the second vacuum pump down measurement can be established based on timing information obtained for the first vacuum pump or source, or can be obtained by using a second sensor. In the case of using a single sensor 120, based on the detection obtained for the timing of the first position sensor, the natural timing of the machine can be used so that the second reading can be associated with a specific vacuum chamber using the expected timing increments between workstations within the machine.

In addition, when it is determined that the vacuum level achieved in the vacuum chamber is insufficient for production purposes, an additional sensor 122 can be used to designate a particular product/package combination as defective. Since the vacuum packaging equipment 100 typically operates in cycles, with each cycle having a fixed time increment or a set of determined positions, the downstream position of the package can be determined based on the amount of time that has passed since the unsuitable vacuum level was reached (which can be considered to use "cycles" as a unit of measurement). For example, if a particular product/package combination is packaged in the vacuum chamber during cycle X, it is known that the product/package combination took 20 cycles to reach the diverter, and then after the insufficient vacuum is identified, the package that reached the diverter 20 cycles can be diverted from the line for recycling. Since the production line may not operate in a continuous manner, and since diverting acceptable product/package units is undesirable, the sensor 116 can be used to count the number of cycles that have occurred since it was determined that an unacceptable vacuum was achieved, so that the unacceptable product/package combination can be diverted when the actual number of cycles is reached.

The sensor system described above can be monitored by a programmable logic controller or other data acquisition system so that the vacuum achieved can be measured, recorded, and associated with the individual chamber/platen combinations. The programmable logic controller or other data acquisition system can have additional capabilities that allow the system to proactively influence downstream product/package combinations, such as by diverting insufficient vacuum from the line to, for example, a repackaging area if insufficient vacuum is drawn before the package is sealed.

Depending on the user's expectations, the system can operate in passive or active mode. In the case of passive monitoring, the functions required to implement active monitoring can be removed, such as removing the components required to allow product/package components to be diverted away from the production line downstream of the vacuum packaging equipment.

In the simplest passive monitoring system, the system can record the vacuum level achieved for a single vacuum chamber associated with the vacuum packaging system. In this simple case, the data can be stored for subsequent review by one or more operators or other maintenance personnel (e.g., at the end of the day) to ensure proper equipment function. The data log can record the platen identifier, the chamber lid identifier, and/or the vacuum achieved for the platen. In the case of multiple vacuum stages, the system can record the vacuum achieved at each stage.

In the case where the system uses an equal number of chamber lids and platens, for example, a machine using four platens and four chamber lids, a display can be provided for each platen/chamber lid combination. Typically, in a four-chamber lid, four-platen system, the same platen can be coupled to the same chamber lid each time the sequence is cycled, so that only four platen/chamber lid combinations need to be recorded. In the case where the number of platens and chamber lids is different, such as (for illustrative purposes) a four-platen, three-chamber lid system, there is the possibility that each platen will eventually be associated with each chamber lid, so that data recording needs to be performed for these combinations, i.e., chamber lid "1", platen "1" (or 1, 1); chamber lid "2", platen "2" (or 2, 2); chamber lid "3", platen "3" (or 3, 3); then chamber lid "1" coupled to platen "4" (or 1, 4); chamber lid "2" coupled to platen "1" (or 2, 1), etc. Thus, it can be seen that a matrix such as that illustrated in FIG. 2 , which illustrates a seven chamber lid, twelve platen system, can be formed to identify chamber lid/platen combinations.

This matrix structure can be used as an identifier for each data set (i.e., which chamber lid/platen combination applied vacuum at what time and to what vacuum level, allowing the data to be sorted based on time, chamber lid, platen, and/or achieved vacuum level, enabling the detection and presentation of performance trends). For example, if the vacuum achieved decreases over time regardless of the platen/chamber lid combination, this could be considered a vacuum pump issue. If the performance degradation occurs only for a specific platen or chamber lid, or a specific platen/chamber lid combination, that specific platen/chamber lid, or platen/chamber lid combination, would be considered a potential cause of the performance degradation.

The system can also be provided with a display to enable real-time performance display to the vacuum packaging system operator. In such a system, the display can provide an indication of the performance of the most recent platen/chamber lid combinations in a matrix format, with the performance coded so that deviations from expected performance can be quickly identified. Such a display is illustrated in Figure 3, which illustrates a display for a ten-platen, six-chamber lid system. The matrix of possible combinations can be displayed by associating platens with columns 302 and chamber lids 304 with rows, such that the combination of platen "3" and chamber lid "5" has an associated performance indicator 306 shown in the fifth row, third column of the matrix. This indicator can be a simple color block, such as a color block, indicating whether the achieved vacuum is acceptable for packaging requirements. For example, sufficient vacuum is indicated in green, marginal vacuum in yellow, and insufficient vacuum in red. Associated numerical data, such as the achieved vacuum value in Torr, can also be displayed. Additional performance data associated with the system may also be displayed, such as information on packages processed per minute, average vacuum readings for all platen/chamber lid combinations over a given period, and possibly at multiple vacuum levels.

As can be seen from the display of Figure 3, there is a possibility that not all matrix positions are used, such as the case where the numbers of pressure plates and chamber covers are both even, so that the matrix positions of those combinations that do not appear (for example, pressure plate "2" chamber cover "1", pressure plate "4" chamber cover "1") may be blank.

As shown in Figures 4 and 5 , an interface can be provided for setting parameters for performance indicators, such as thresholds 502a, 502b, 502c, 502d, 502e, etc., for achieving acceptable vacuum levels. Furthermore, an interface can be provided to allow an operator to review the historical performance of a particular chamber/platen combination, thereby enabling assessment of trends. Thus, real-time trend information, such as that shown in Figures 6, 7, and 8, can be generated as needed for operator analysis.

In a complete implementation, the system can be implemented so that, based on the vacuum readings obtained, packages produced by the chamber cover/platen combination that have achieved insufficient vacuum can be diverted to a disposal or repackaging area. This system shown in Figure 1 can use tracking of specific packages that have achieved insufficient vacuum so that a diverter (not shown) can divert this specific package out. In the case where the system uses a cycle counter 116 that increments whenever a completed package leaves the vacuum packaging unit 100, cycle counting can be used to determine when a specific package arrives at a downstream location. For example, it can be known that each package takes ten cycles to reach the downstream diverter, and packages that have achieved insufficient vacuum will be located at the diverter station after ten cycles. In this way, a vacuum measurement technology solution can be implemented to achieve automatic rejection of packages based on the vacuum achieved.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes of the present invention. Accordingly, reference is made to the appended claims rather than the foregoing description to indicate the scope of the present invention.

Claims (19)

1. A monitoring system for a vacuum packaging machine, the vacuum packaging machine comprising a plurality of pressure plates and chamber covers and a vacuum pump for pumping air from a vacuum chamber formed by the pressure plates and chamber covers, the monitoring system comprising: A vacuum sensor, communicatively connected to the vacuum chamber, measures the pressure level in the vacuum chamber formed by one of the plurality of pressure plates and a chamber cover; Pressure plate identifier, used to identify at least one pressure plate used to form a vacuum chamber to which the vacuum sensor can be communicatively connected; A chamber cover identifier for identifying at least one chamber cover used to form a vacuum chamber to which the vacuum sensor is communicatively connected; and A controller system for recording a vacuum achieved in the vacuum chamber for the at least one pressure plate and chamber cover that are combined to form the vacuum chamber, wherein the controller system also records information from the pressure plate identifier and the chamber cover identifier that identifies which of the at least one pressure plate and the at least one chamber cover are combined to form the vacuum chamber, wherein different combinations of the pressure plate and the chamber cover are possible. 2. The monitoring system according to claim 1, wherein the number of pressure plates and the number of chamber covers are not equal. 3. The monitoring system of claim 1, wherein the controller system further includes logic for comparing the achieved vacuum level with a predetermined threshold. 4. The monitoring system of claim 3, further comprising a display that displays a visual indication when the achieved vacuum does not meet the predetermined threshold. 5. The monitoring system of claim 3, wherein the controller system generates a rejection signal when the achieved vacuum does not meet the predetermined threshold. 6. The monitoring system of claim 1, wherein the controller system records the vacuum achieved in the vacuum chamber for a plurality of pressure plate and chamber cover combinations. 7. The monitoring system of claim 6, wherein the vacuum achieved in the vacuum chamber is displayed to the operator in matrix form on a display for a plurality of pressure plate and chamber cover assemblies. 8. The monitoring system of claim 1, wherein the vacuum packaging machine further includes a package sensor for determining when a particular pressure plate has product on it. 9. The monitoring system of claim 8, wherein the controller system further includes logic for comparing an achieved vacuum level with a predetermined threshold, the controller system generating a rejection signal when the achieved vacuum does not meet the predetermined threshold, and the monitoring system further includes a deflector that, when the controller system generates the rejection signal, deflects a vacuum-packed product in a specific pressure plate and chamber cover combination. 10. A vacuum packaging machine for vacuum packaging products, the vacuum packaging machine comprising: Multiple pressure plates; Multiple chamber covers, which are coupled to the pressure plate to form a vacuum chamber and allow different combinations of the pressure plate and the chamber covers to be associated, the vacuum chamber being able to be formed by different combinations of the pressure plate and the chamber covers; A vacuum source is selectively connected to the vacuum chamber; A vacuum sensor is selectively connected to the vacuum chamber; Identifiers are attached to each pressure plate and chamber lid associated with the vacuum packaging machine; and A controller system is configured to record the vacuum achieved in the vacuum chamber when the vacuum source is selectively connected to the vacuum chamber. The controller system also records information from the identifier attached to each pressure plate and chamber cover, which identifies which pressure plate and which chamber cover constitute the vacuum chamber when the achieved vacuum is recorded. 11. The vacuum packaging machine of claim 10, wherein the vacuum packaging machine further includes a package sensor that determines when a particular pressure plate has product on it. 12. The vacuum packaging machine of claim 10, wherein the controller system further includes logic for comparing the achieved vacuum with a predetermined threshold. 13. The vacuum packaging machine of claim 12, further comprising a deflector that deflects the product when the vacuum achieved in the pressure plate and chamber cover assembly does not meet the predetermined threshold. 14. The vacuum packaging machine according to claim 12, further comprising a display unit, the display showing the vacuum achievement result for the combination of the pressure plate and the chamber cover. 15. The vacuum packaging machine according to claim 14, wherein the vacuum achievement results are displayed on the display in matrix form. 16. The vacuum packaging machine of claim 15, wherein the vacuum achievement result is displayed using encoding to indicate whether the vacuum achievement result meets the predetermined threshold. 17. The vacuum packaging machine of claim 15, further comprising: a second vacuum pump selectively connected to the vacuum chamber and a second vacuum sensor selectively connected to the vacuum chamber, wherein the controller system records a second vacuum level achieved in association with the vacuum chamber via the second vacuum sensor. 18. The vacuum packaging machine of claim 17, wherein the controller system further includes logic for comparing the achieved second vacuum with a second predetermined threshold. 19. The vacuum packaging machine of claim 18, wherein the display further displays the second vacuum achievement result for the combination of the pressure plate and the chamber cover.